This invention relates generally to noise attenuation, and more specifically to means for minimizing the intensity of sound produced in the exhaust system of an air pressure operated motor, commonly referred to as a pneumatic motor.
The noise from a pneumatic motor is caused by the flow of high velocity air under pressure, and containing high impulses created by the sudden opening and closing of the exhaust ports in the cylinder in which the rotor revolves. While many efforts have been made to attenuate such impulses, none of them so far as I am aware has embodied the unusual advantages in structure, mode of operation and results as are now afforded by the present invention. Among these are the advantages of extreme compactness, simplicity, high attenuation and control of exhaust escape flow, as will be seen.